Signaling system for telephone-circuits



(No Model.) J. I. SABIN & W. HAMPTON.

SIGNALING SYSTEM FOR TELEPHONE GIRGU ITS.

No. 513,534. Patented Jan. 30, 1894."

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JOHN I. SABIN AND WILLIAM HAMPTON, OF SAN FRANCISCO, CALIFORNIA.

NrrE' SIGNALING SYSTEM FOR TELEPHONE-ClRC UITS.

SPECIFICATION forming part of Letters Patent No. 513,534, dated January30, 1894.

Application filed August 18, 1893. Serial No. 483,480- (No model.)

To all whom it may concern.-

Be it known that we, JOHN I. SABIN and WILLIAM HAMPTON, citizens of theUnited States, residingin the city and county of San Francisco and Stateof California, have invented certain new and useful Improvements inSubscribers-Station Signaling Systems for Telephone-Circuits, of whichthe following is a specification.

Our invention relates to improvements in signaling or calling theoperator at a switching-station from the subscribers-station in metalliccircuit telephone systems.

The object of our improvement is to provide means or apparatus by whichthe subscriber operates an indicator, or visual signal, at theswitching-station automatically by the act of removing his telephonefrom its hook; therebydispensin g entirely withthe operation ofringing-up the station and saving the time consumed in securing theattention of the operator by means of the magneto-generator at thesubscribers telephone heretofore provided for the purpose.

Our invention is applicable more particularly to metallic circuits, andit consists, essentially of a signaling circuit at the stationswitch-board comprising a subscribers calling-indicator, or visualsignal, and a battery to which the indicator is permanently connected,in combination with a subscribers metallic circuit composed of two wiresopen or separated at the subscribers end, but connected at theswitch-board to both sides of the calling-indicator circuit, and ashunt-or short-circuit bridging the subscribers circuit at histelephone, which shunt contains the subscribers local transmitting andreceiving circuit and his telephone-switch. These parts are so arrangedand combined for operation that when the subscribers telephone-switch isin its lowest position, that is, when his receiver is hung up, the shuntis broken and the calling-indicator circuit at the switchingstationstands open, because the two wires of the main circuit are separated atthe subscribers end of the line; but as soon as the subscriber removeshis telephone from its hook the shunt unites electrically the two wiresof the subscribers line, and conse-* quently closes the circuit of theindicatorbattery through the indicator. In connection with this systemof circuits we provide means of calling-up the subscriber from theswitching-station, the same consisting in grounding one wire of thesubscribers-line through his telephone-switch and his bell-signalwhereby the operator calls up the subscriber by throwing a battery atthe switch-board upon the grounded wire of the subscribers line in theusual way.

Our said invention is illustrated in the accompanying drawing to whichreference is made in the following description by figures and letters.

The drawing illustrates the metallic circuits of three separatesubscribers lines and their connections at the station switch-board withindividual calling-indicators.

A A A? indicate the spring jack connections at the switch-board of threetelephone circuits each circuit being composed of two line wires 12.

B is the battery of a local circuit at the switch-board, and O*- is acalling-indicator, or visual signal, for each subscribers line placed inthe circuit between the two sides of the battery; the wires of thebattery circuit are indicated at -34. The connection of this indicatorto the two sides of the battery -B- is made through a four-point jack inthe switch-board the springs a a ot the jack forming the terminals ofthe line wires 1-2 and the points a -a, of the jack being connected tothe battery wires -34;- by the wires -56. Thus the circuit from one sideof the battery is through one wire --3- and its connection -5- to thepoint -a and through the spring -a to one side of the subscribers line;and from the other-side of the battery through the wire -4- and itsconnection -6- to the point -a and through the spring a, to the otherside of the line. The subscribers indicator -O is located in thiscircuit between one side of the battery and one of the points (-0t or 06of the spring-jack.

The two line wires 1-2 are perma nently separated at the subscribers endof the line, but at the switch-board they are closed upon the localindicator-circuit when the switching-plugs are out, and in that positionof the springs -'-aa they are a part of the battery circuit. By unitingthe two wires 1-2- at the subscribers telephone, therefore, thebattery-circuit is closed, and the indicator -O located in that circuitwill be operated by the flow of the current over the line. i

DDD indicate the hand-telephones, and E-EE the switch-levers and hooksfor the telephone in the three subscribers circuits.

F-F'- are the wires of the subscribers local transmitting and receivingcircuit, and F indicates the induction-coilof that circuit.

G- and G' are two anvils or contacts on opposite sides of theswitch-lever; the upper one being set for contact with the lever whenthe weight of the telephone is removed from the hook and the lever isthrown up by its spring f-, and the lower one G having contact when thelever is held down by the weight-of the telephone on its hook.

The wires FF of the local circuit are permanently connected to the uppercontact -G- and to one line-wire of the subscribers line, while theother wire of theline is attached to the switch-lever asindicated at g,so that the two wires of the line are closed by the shunt as soon as theswitch-lever sets in contact with G. The metallic circuit is establishedfor conversation, therefore, as soon as the handtelephone is removedfrom its hook; and at the same time the battery B is thrown upon thecalling-indicator at the switchingstation. On the other hand, theindicatorbattery circuit stands open through the linewires and theindicator will not operate as long as the switch-lever rests in contactwith the lower anvil G. To this contact -G' the mechanism of thebell-signal is connected by the wire h and is grounded by the wire h-;so that the circuit of the linewire which is permanently connected tothe switch-lever is through the bell-signal to the ground -X. Theordinary bell-signal can be used for the purpose; and in the position ofthe parts as before described, when the hand-telephone is on its hookand the metallic circuit stands open at the subscrib' ers end of theline, the operator is enabled to signal on one wire of the subscribersline by throwing a battery upon that wire at the switch-board in thesame manner as bell-signals are operated at the present time to callupthe subscriber.

In the accompanying diagram the circuits of the subscribers A- and A areclosed, and the battery is flowing through the indicators, because theline wires 12- are united by the subscribers shunt; while the circuit ofthe subscriber A' is open and the indicator battery is off, because thehandtelephone is on its hook and the two line-wires are separated.

One battery can be employed to operate any number of calling-indicatorsby connecting them to the wires of the battery-circuits as we have shownin the diagram.

Having thus fully described our invention, what we claim as new, anddesire to secure by Letters Patent, is-

1. Individual calling-indicators on a local battery circuit, incombination with subscribers metallic circuits each composed of twoline-wires connected to opposite sides of the said local circuit at theswitch-board to form part of said local circuit, and means for unitingthe two line-wires at the subscribers telephone to close the batteryupon the said indicators, substantially as described.

2. In a telephone-system, a subscribers circuit composed of twoline-wires normally separated at the subscribers station, in combinationwith a calling-indicator circuit at the switching-station consisting ofa battery and a calling-indicator in circuit with said battery throughthe subscribers line and ashunt or short-circuit adapted to connect thetwo wires of the subscribers line and close the circuit of theindicator, said shunt including the subscribers hand-telephone and histelephone-switch, substantially as described, for operation as setforth.

3. In a telephonesystem, the combination of a subscribers circuitcomposed of two linewires normally separated at the subscribers station,a local circuit at the switching-station in which is included acalling-indicator and a battery, and four-point spring-jack connectionsat the switch-board by which the two wires of the subscribers line areconnected to and made a part of the said local circuit, a shunt or shortcircuit adapted to close the two sides of the subscribers line, and aswitchlever having two anvils, or contacts, to one of which said shuntis connected, and to the other of which is connected a bell-signal and aground, the lever of said switch being the subscribers telephone-hookwhereby the circuit of the indicator-battery is closed through theindicators by the'act of removing the telephone from its hook, and oneside of the subscribers line is grounded through the bellsignal when thetelephone is hanging on its hook, as hereinbefore described, foroperation as set forth.

In testimony that we claim the foregoing we have hereunto set our handsand seals.

JOHN I. SABIN. [L. 3.] WILLIAM HAMPTON. [L. 8.] Witnesses:

EDWARD E. 0513mm, 0. W. M. SMITH.

